KR20140024294A - Computerized tool path generation - Google Patents

Abstract

An automated computer-implemented method of generating instructions for controlling a computer numerical control machine to manufacture an object from a workpiece, the method comprising: selecting a maximum allowable engagement angle between the rotary cutting tool and the workpiece, the rotary cutting tool and the Selecting a minimum allowable engagement angle between workpieces, establishing a tool path for the tool for the workpiece wherein the engagement angle is gradually changed between the maximum allowable engagement angle and the minimum allowable engagement angle. A method is provided.

Description

COMPUTER TOOL PATH GENERATION}

The present invention relates to systems and methods for automated tool path design and computer controlled machining and products produced thereby.

The following disclosures are believed to be indicative of the current state of the art and are incorporated herein by reference:

US Patent No .: 4,745,558; 4,907,164; 5,363,308; 6,363,298; 6,447,223; 6,591,158; 7,451,013; 7,577,490, and 7,831,332; And

US Patent Publication No. 2005/0256604.

The present invention seeks to provide systems and methods for automated tool path design and computer controlled machining and the products produced thereby.

In accordance with another preferred embodiment of the present invention, an automated computer-implemented method of generating instructions for controlling a computer numerical control machine to manufacture an object from a workpiece, the method comprising: a maximum permissible engagement angle between a rotary cutting tool and the workpiece selecting a maximum permitted engagement angle, selecting a minimum allowable engagement angle between the rotary cutting tool and the workpiece, and wherein the engagement angle is gradually between the maximum allowable engagement angle and the minimum allowable engagement angle. A method is provided that includes setting a tool path for the tool to varying workpieces.

According to a preferred embodiment of the invention, in response to the consideration of at least one of the characteristics of the computer numerical control machine, the rotary cutting tool and the workpiece material, the setting step also depends on time, while applying other constraints. Minimizing the rate of change of the engagement angle, gradually changing the feed rate of the tool in response to the changing engagement angle, maintaining an overall constant workload for the tool, and manufacturing costs of the article Minimizing, whereby the cost is a combination of the cost of operating the machine during the period of manufacture and the cost of wear applied to the tool during the period of manufacture.

Advantageously, said tool path comprises a plurality of tool path segments, and said tool path setting step includes recursively setting each of said tool path segments, wherein a computer numerical control machine, a rotary cutting tool, and said In response to taking into account at least one of the properties of the material of the workpiece, setting each of the tool path segments also minimizes the rate of change of the engagement angle over time, while applying other constraints. Gradually changing a feed rate of the tool in response to an engagement angle, maintaining an overall constant work load for the tool, and minimizing the cost of machining each of the tool path segments; Whereby the cost of operating the machine during the period of machining Cost and the cost of wear applied to the tool during the machining period.

Additionally, each of the tool path segments includes a plurality of tool path subsegments, and recursively setting each of the tool path segments includes recursively setting each of the tool path subsegments; Wherein, in response to taking into account at least one of the computer numerical control machine, the rotary cutting tool and the properties of the material of the workpiece, the step of setting each of the tool path subsegments may also be performed by applying different constraints. Minimizing a rate of change of the engagement angle in accordance with the method, gradually changing a feed rate of the tool in response to the changing engagement angle, maintaining an overall constant work load for the tool, and the tool path sub Minimizing the cost of machining each of the segments, and The cost is thereby a combination of the cost of operating the machine during the period of machining and the wear cost imposed on the tool during the period of machining.

Further in accordance with another preferred embodiment of the present invention, a method for machining a workpiece employing a computer controlled machine tool is provided, the method comprising directing the tool along a tool path, wherein the The engagement angle between the tool and the workpiece is gradually changed between a preselected maximum allowable engagement angle and a preselected minimum allowable engagement angle.

In addition, an automated computer-implemented device for generating instructions for controlling a computer numerical control machine for manufacturing an object from a workpiece according to another preferred embodiment of the present invention, wherein the engagement angle is a preselected maximum allowable engagement angle. And a tool routing engine operable to set a tool path for a tool for the workpiece that varies gradually between a preselected minimum allowable engagement angle.

Advantageously, said setting step comprises minimizing the rate of change of said engagement angle with time, while applying other constraints. Advantageously, said setting step also comprises gradually changing the feed rate of said tool in response to said varying engagement angle. Advantageously, said setting step also operates to maintain an overall constant workload for said tool. Preferably, the setting step also operates to minimize the cost of manufacturing the article, such that the cost is a combination of the cost of operating the machine during the manufacturing period and the cost of wear applied to the tool during the manufacturing period. . The preferred features referenced in this paragraph are also applicable to all suitable claimed embodiments of the invention.

Advantageously, said tool path comprises a plurality of tool path segments, and said tool path setting step includes recursively setting each of said tool path segments, wherein setting each of said tool path segments comprises: Further, while applying other constraints, minimizing the rate of change of the engagement angle over time, gradually changing the feed rate of the tool in response to the varying engagement angle, and the overall constant workload for the tool And minimizing the cost of machining each of the tool path segments, whereby the cost is the cost of operating the machine during the period of machining and the tool during the machining period. It is a combination of the wear costs incurred for. The preferred features referenced in this paragraph are also applicable to all suitable claimed embodiments of the invention.

Advantageously, each of said tool path segments comprises a plurality of tool path subsegments, and recursively setting each of said tool path segments comprises recursively setting each of said tool path subsegments. And wherein setting each of the tool path subsegments further comprises minimizing a rate of change of the engagement angle over time, while applying other constraints, the feed rate of the tool corresponding to the varying engagement angle. Gradually varying, maintaining an overall constant workload for the tool, and minimizing the cost of machining each of the tool path subsegments, whereby the cost of the machining The cost of operating the machine during the period and It is the combination of the applied wear costs for the tools. The preferred features referenced in this paragraph are also applicable to all suitable claimed embodiments of the invention.

Advantageously, said step of setting includes taking into account at least one of a property of said computer numerical control machine, a rotary cutting tool and a material of said workpiece. The preferred features referenced in this paragraph are also applicable to all suitable claimed embodiments of the invention.

According to another preferred embodiment of the present invention, an automated computer controlled machine for manufacturing an object from a workpiece, wherein the engagement angle between the tool and the workpiece is a preselected maximum allowable engagement angle and a preselected minimum allowable engagement angle. A machine is provided that includes a controller operative to direct a rotational cutting tool along a tool path with respect to the workpiece that changes gradually between.

According to another preferred embodiment of the present invention, an object is provided from a workpiece machined using a computer controlled machine by directing a rotary cutting tool along a tool path, wherein the rotary cutting tool and the workpiece are provided. The engagement angle between is gradually changed between the preselected maximum allowable engagement angle and the preselected minimum allowable engagement angle.

According to another preferred embodiment of the present invention, an automated computer-implemented method of generating instructions for controlling a computer numerical control machine for manufacturing an article from a workpiece, wherein the area of the workpiece to be removed by the rotary cutting tool is selected. And establishing an asymmetrical spiral tool path for the rotary cutting tool in the area of the workpiece, the asymmetrical spiral tool path being driven by the rotary cutting tool moving along the asymmetrical spiral tool path. Further provided are methods for maximizing a portion of the area of the workpiece to be removed.

Preferably, the method also includes establishing at least one trocoid-like tool path for a rotary cutting tool in the remaining portion of the area of the workpiece removed by the tool moving along the trochoidal tool path. Include.

Preferably, the method further comprises selecting a maximum allowable engagement angle between the rotary cutting tool and the workpiece, selecting a minimum allowable engagement angle between the rotary cutting tool and the workpiece, and wherein the engagement angle is Establishing the asymmetrical spiral tool path and the at least one trocoid-like tool path for the workpiece to cause a gradual change between the maximum allowable engagement angle and the minimum allowable engagement angle.

Advantageously, in response to consideration of at least one of the characteristics of the computer numerical control machine, the rotary cutting tool, and the workpiece material, the setting step also applies a different constraint, with the rate of change of the engagement angle over time. Minimizing the number of steps; gradually varying the feed rate of the tool in response to the varying engagement angle, maintaining an overall constant workload for the tool, and minimizing the manufacturing cost of the article. Whereby the cost is a combination of the cost of operating the machine during the period of manufacture and the wear cost imposed on the tool during the period of manufacture.

Advantageously, said asymmetrical helix tool path comprises a plurality of helix tool path segments, said at least one trocoided tool path comprises a plurality of trocoid-shaped tool path segments, and wherein said asymmetrical helix tool path setting step comprises said helix tool. Recursively setting each of the path segments, wherein at least one trocoid-type tool path setting step includes recursively setting each of the trocoid-type tool path segments, wherein the computer numerical control machine, In response to taking into account at least one of the properties of the rotational cutting tool and the material of the workpiece, setting each of the tool path segments also minimizes the rate of change of the engagement angle over time while applying other constraints. In response to the varying engagement angle of the tool. Gradually varying the feed rate, maintaining an overall constant workload for the tool, and minimizing the cost of machining each of the tool path segments, thereby costing the machining It is a combination of the cost of operating the machine for a period of time and the wear cost imposed on the tool during the machining period.

Additionally, each of the tool path segments includes a plurality of tool path subsegments, and recursively setting each of the tool path segments includes recursively setting each of the tool path subsegments; Wherein, in response to taking into account at least one of the computer numerical control machine, the rotary cutting tool and the properties of the material of the workpiece, the step of setting each of the tool path subsegments may also be performed by applying different constraints. Minimizing a rate of change of the engagement angle in accordance with the method, gradually changing a feed rate of the tool in response to the changing engagement angle, maintaining an overall constant work load for the tool, and the tool path sub Minimizing the cost of machining each of the segments, and The cost is thereby a combination of the cost of operating the machine during the period of machining and the wear cost imposed on the tool during the period of machining.

Preferably, the asymmetric spiral tool path is one of a converging spiral tool path and a diverging spiral tool path.

According to another preferred embodiment of the present invention, a method for machining a workpiece by employing a computer controlled machine tool, comprising: selecting an area of the workpiece to be removed by the rotary cutting tool, and an area of the workpiece Directing the tool along an asymmetrical spiral tool path within, wherein the asymmetrical spiral tool path is a portion of an area of the workpiece that is removed by the rotary cutting tool moving along the asymmetrical spiral tool path. More ways to maximize are provided. Advantageously, the method also comprises directing said rotary cutting tool along at least one trocoid-like tool path in the remaining portion of the area of said workpiece that is removed by a tool moving along the trocoid-like tool path. .

According to another preferred embodiment of the present invention, an automated computer-implemented device for generating instructions for controlling a computer numerical control machine for manufacturing an object from a workpiece, wherein the area of the workpiece to be removed by the rotary cutting tool is selected. And a tool path setting engine for setting an asymmetric spiral tool path for the rotary cutting tool in the area of the workpiece, the spiral tool path being driven by the rotary cutting tool moving along the asymmetric spiral tool path. Further provided is an apparatus for maximizing a portion of the area of the workpiece to be removed.

Advantageously, the tool routing engine is further configured to set at least one trocoid-like tool path for the rotary cutting tool in the remaining portion of the area of the workpiece that is removed by the tool moving along the trocoid-like tool path. It works.

Advantageously, the setting step includes selecting a maximum allowable engagement angle between the rotary cutting tool and the workpiece, selecting a minimum allowable engagement angle between the rotary cutting tool and the workpiece, and wherein the engagement angle is Establishing the asymmetrical spiral tool path and the at least one trocoid-like tool path for the workpiece to cause a gradual change between the maximum allowable engagement angle and the minimum allowable engagement angle.

Advantageously, said setting step comprises minimizing the rate of change of said engagement angle over time, while applying other constraints. Advantageously, said setting step also comprises gradually changing the feed rate of said tool in response to said varying engagement angle. Advantageously, said setting step also operates to maintain an overall constant workload for said tool. Advantageously, the setting step also includes minimizing the manufacturing cost of the article, whereby the cost is a measure of the cost of operating the machine during the period of manufacture and the cost of wear applied to the tool during the manufacture. It is a combination.

Advantageously, said asymmetrical helix tool path comprises a plurality of helix tool path segments, said at least one trocoided tool path comprises a plurality of trocoid-shaped tool path segments, and wherein said asymmetrical helix tool path setting step comprises said helix tool. Recursively setting each of the path segments, wherein at least one trocoid-type tool path setting step includes recursively setting each of the trocoid-type tool path segments, wherein the computer numerical control machine, In response to taking into account at least one of the properties of the rotational cutting tool and the material of the workpiece, setting each of the tool path segments also minimizes the rate of change of the engagement angle over time, taking into account other constraints. In response to the varying engagement angle of the tool. Gradually varying the feed rate, maintaining an overall constant workload for the tool, and minimizing the cost of machining each of the tool path segments, thereby costing the machining It is a combination of the cost of operating the machine for a period of time and the wear cost imposed on the tool during the machining period.

Additionally, each of the tool path segments includes a plurality of tool path subsegments, and recursively setting each of the tool path segments includes recursively setting each of the tool path subsegments; Wherein, in response to taking into account at least one of the computer numerical control machine, the rotary cutting tool and the properties of the material of the workpiece, the step of setting each of the tool path subsegments may also be performed by applying different constraints. Minimizing a rate of change of the engagement angle in accordance with the method, gradually changing a feed rate of the tool in response to the changing engagement angle, maintaining an overall constant work load for the tool, and the tool path sub Minimizing the cost of machining each of the segments, and The cost is thereby a combination of the cost of operating the machine during the period of machining and the wear cost imposed on the tool during the period of machining.

Preferably, the asymmetric spiral tool path is one of a converging spiral tool path and a diverging spiral tool path.

According to another preferred embodiment of the present invention, an automated computer controlled machine for manufacturing an object from a workpiece, wherein the area of the workpiece to be removed by a rotary cutting tool is selected and asymmetric within the area of the workpiece A controller operative to direct the rotary cutting tool along the spiral tool path, wherein the spiral tool path maximizes a portion of the area of the workpiece that is removed by the rotary cutting tool moving along the asymmetric spiral tool path. The machine is further provided.

Advantageously, said controller is further adapted to direct said rotary cutting tool along at least one trocoid-like tool path in the remainder of the area of said workpiece removed by said tool moving along said trocoid-like tool path. It works.

According to another preferred embodiment of the present invention, a computer is provided by selecting an area of the workpiece to be removed by a rotary cutting tool and directing the rotary cutting tool along an asymmetric spiral tool path within the region of the workpiece. An article manufactured from a workpiece that is machined using a control machine tool, wherein the article that maximizes the portion of the area of the workpiece that is removed by the rotating cutting tool that moves along the asymmetric spiral tool path. More is provided.

Preferably, the article is manufactured by directing the rotary cutting tool along at least one trocoid-like tool path in the remainder of the area of the workpiece that is removed by the tool moving along the trocoid-like tool path.

According to another preferred embodiment of the present invention, an automated computer-implemented method of generating instructions for controlling a computer numerical control machine for manufacturing an article from a workpiece, wherein the area of the workpiece to be removed by the rotary cutting tool is selected. Selecting a first portion of the region to be removed by an asymmetrical spiral tool path, and establishing at least one trocoid-like tool path to remove the remaining portion of the region; Selecting one portion further provides a method that operates to minimize the machining time required to remove the area.

Advantageously, the method further comprises selecting a maximum allowable engagement angle between a tool and said workpiece, selecting a minimum allowable engagement angle between said tool and said workpiece, and wherein said engagement angle is said maximum allowable engagement. Establishing the asymmetrical spiral tool path and the at least one trocoid-like tool path for the workpiece to cause a gradual change between an angle and the minimum allowable engagement angle.

Preferably, in response to consideration of at least one of the characteristics of the computer numerical control machine, the rotary cutting tool and the workpiece material, the setting step also takes into account other constraints, the rate of change of the engagement angle over time. Minimizing the number of steps; gradually varying the feed rate of the tool in response to the varying engagement angle, maintaining an overall constant workload for the tool, and minimizing the manufacturing cost of the article. Whereby the cost is a combination of the cost of operating the machine during the period of manufacture and the wear cost imposed on the tool during the period of manufacture.

Advantageously, said asymmetrical helix tool path comprises a plurality of helix tool path segments, said at least one trocoided tool path comprises a plurality of trocoid-shaped tool path segments, and wherein said asymmetrical helix tool path setting step comprises said helix tool. Recursively setting each of the path segments, wherein at least one trocoid-type tool path setting step includes recursively setting each of the trocoid-type tool path segments, wherein the computer numerical control machine, In response to taking into account at least one of the properties of the rotational cutting tool and the material of the workpiece, setting each of the tool path segments also minimizes the rate of change of the engagement angle over time while applying other constraints. In response to the varying engagement angle of the tool. Gradually varying the feed rate, maintaining an overall constant workload for the tool, and minimizing the cost of machining each of the tool path segments, thereby costing the machining It is a combination of the cost of operating the machine for a period of time and the wear cost imposed on the tool during the machining period.

Advantageously, each of said tool path segments comprises a plurality of tool path subsegments, and recursively setting each of said tool path segments comprises recursively setting each of said tool path subsegments. And in response to taking into account at least one of the properties of the computer numerical control machine, the rotary cutting tool and the material of the workpiece, the step of setting each of the tool path subsegments also applies other constraints, Minimizing the rate of change of the engagement angle over time, gradually changing the feed rate of the tool in response to the changing engagement angle, maintaining an overall constant workload for the tool, and the tool path Minimizing the cost of machining each of the subsegments; Whereby the cost is a combination of the cost of operating the machine during the period of machining and the cost of wear applied to the tool during the period of machining.

Preferably, the asymmetric spiral tool path is one of a converging spiral tool path and a diverging spiral tool path.

According to another preferred embodiment of the present invention, there is provided a method for machining a workpiece employing a computer controlled machine tool, comprising: selecting an area of the workpiece to be removed by a rotary cutting tool, by means of an asymmetrical spiral tool path Selecting a first portion of the region to be removed, and directing the tool along at least one trocoid-like tool path within the remaining portion of the region of the workpiece, the first portion of the region The step of selecting is operative to minimize the machining time required to remove the area.

According to another preferred embodiment of the present invention, an automated computer-implemented device for generating instructions for controlling a computer numerical control machine for manufacturing an object from a workpiece, wherein the area of the workpiece to be removed by the rotary cutting tool is selected. And a tool routing engine operative to select a first portion of the region to be removed by an asymmetric spiral tool path, and to establish at least one trocoid-like tool path for removing the remaining portion of the region. And selecting the first portion of the region operates to minimize the machining time required to remove the region.

Advantageously, the setting step includes selecting a maximum allowable engagement angle between the rotary cutting tool and the workpiece, selecting a minimum allowable engagement angle between the rotary cutting tool and the workpiece, and wherein the engagement angle is Establishing the asymmetrical spiral tool path and the at least one trocoid-like tool path for the workpiece to cause a gradual change between the maximum allowable engagement angle and the minimum allowable engagement angle.

Advantageously, said setting step comprises minimizing the rate of change of said engagement angle over time, while applying other constraints. Advantageously, said setting step also comprises gradually changing the feed rate of said tool in response to said varying engagement angle. Advantageously, said setting step also operates to maintain an overall constant workload for said tool. Advantageously, said setting step also operates to minimize manufacturing cost of said article, whereby said cost is a combination of the cost of operating said machine during said period of manufacture and the cost of wear applied to said tool during said period of manufacture. to be.

Advantageously, said asymmetrical helix tool path comprises a plurality of helix tool path segments, said at least one trocoided tool path comprises a plurality of trocoid-shaped tool path segments, and wherein said asymmetrical helix tool path setting step comprises said helix tool. Recursively setting each of the path segments, wherein at least one trocoid-type tool path setting step includes recursively setting each of the trocoid-type tool path segments, wherein the computer numerical control machine, In response to taking into account at least one of the properties of the rotational cutting tool and the material of the workpiece, setting each of the tool path segments also minimizes the rate of change of the engagement angle over time while applying other constraints. In response to the varying engagement angle of the tool. Gradually varying the feed rate, maintaining an overall constant workload for the tool, and minimizing the cost of machining each of the tool path segments, thereby costing the machining Is a combination of the cost of operating the machine for a period of time and the wear cost applied to the tool during the machining period.

Additionally, each of the tool path segments includes a plurality of tool path subsegments, and recursively setting each of the tool path segments includes recursively setting each of the tool path subsegments; Wherein, in response to taking into account at least one of the computer numerical control machine, the rotary cutting tool and the properties of the material of the workpiece, the step of setting each of the tool path subsegments may also be performed by applying different constraints. Minimizing a rate of change of the engagement angle in accordance with the method, gradually changing a feed rate of the tool in response to the changing engagement angle, maintaining an overall constant work load for the tool, and the tool path sub Minimizing the cost of machining each of the segments, and Thereby the cost is a combination of the cost of operating the machine during the period of machining and the wear cost imposed on the tool during the period of machining.

Preferably, the asymmetric spiral tool path is one of a converging spiral tool path and a diverging spiral tool path.

According to another preferred embodiment of the present invention, an automated computer controlled machine for manufacturing an article from a workpiece, wherein the area of the workpiece to be removed by the rotary cutting tool is selected and removed by the asymmetrical spiral tool path. A machine is further provided comprising a controller operative to select a first portion of the area and direct the rotary cutting tool along at least one trocoid-like tool path within the area of the workpiece. Selecting the first portion operates to minimize the machining time required to remove the region.

According to another preferred embodiment of the invention, the area of the workpiece to be removed by the rotary cutting tool is selected, the first part of the area to be removed by the asymmetrical spiral tool path is selected, and the Further provided is an article made from a workpiece machined using a computer controlled machine tool by directing the rotary cutting tool along at least one trocoided tool path within the region, and selecting a first portion of the region. And the step of operating to minimize the machining time required to remove the area.

In accordance with another preferred embodiment of the present invention, there is provided an automated computer implemented method for generating instructions for controlling a computer numerical control machine to manufacture an article from the workpiece by removing portions of the workpiece that will not be included in the article. Considering the cross section of the desired object to be manufactured from the workpiece, forming separate regions of the cross section on the workpiece surface that will not be removed as islands, setting up the tool path in the region without islands Is provided, and establishing an arc tool path forming a moat surrounding the island when the tool path encounters the island.

Advantageously, the method comprises establishing a composite region comprising said island, an arc surrounding said island, and islands that have already been removed from said workpiece as removed areas, and said removed areas. Setting a tool path to remove remaining areas of the workpiece that do not.

Advantageously, the method further comprises selecting a maximum allowable engagement angle between a tool and said workpiece, selecting a minimum allowable engagement angle between said tool and said workpiece, and wherein said engagement angle is said maximum allowable engagement. Establishing the arc tool path for the workpiece to cause a gradual change between an angle and the minimum allowable engagement angle.

Advantageously, in response to consideration of at least one of the characteristics of the computer numerical control machine, the rotary cutting tool, and the workpiece material, the setting step also applies different constraints, with the rate of change of the engagement angle over time. Minimizing the number of steps; gradually varying the feed rate of the tool in response to the varying engagement angle, maintaining an overall constant workload for the tool, and minimizing the manufacturing cost of the article. Whereby the cost is a combination of the cost of operating the machine during the period of manufacture and the wear cost imposed on the tool during the period of manufacture.

Additionally, the tool path includes a plurality of tool path segments, and the tool path setting includes recursively setting each of the tool path segments, wherein the computer numerical control machine, the rotary cutting tool and the In response to taking into account at least one of the properties of the material of the workpiece, setting each of the tool path segments also minimizes the rate of change of the engagement angle over time, while applying other constraints. Gradually changing a feed rate of the tool in response to an engagement angle, maintaining an overall constant work load for the tool, and minimizing the cost of machining each of the tool path segments; Whereby the cost is the ratio of operating the machine during the period of machining. And wear costs imposed on the tool during the machining period.

Additionally, each of the tool path segments includes a plurality of tool path subsegments, and recursively setting each of the tool path segments includes recursively setting each of the tool path subsegments; Wherein, in response to taking into account at least one of the computer numerical control machine, the rotary cutting tool and the properties of the material of the workpiece, the step of setting each of the tool path subsegments may also be performed by applying different constraints. Minimizing a rate of change of the engagement angle in accordance with the method, gradually changing a feed rate of the tool in response to the changing engagement angle, maintaining an overall constant work load for the tool, and the tool path sub Minimizing the cost of machining each of the segments, and Thereby the cost is a combination of the cost of operating the machine during the period of machining and the wear cost imposed on the tool during the period of machining.

According to yet another preferred embodiment of the present invention, a method for machining a workpiece by employing a computer controlled machine tool, which takes into account the cross section of the desired object to be manufactured from the workpiece, said workpiece not to be removed as an island. Forming discrete regions of the cross section on the surface, orienting the tool first along a tool path in an area without islands, and forming a moat surrounding the island when the island and tool path meet. Further provided is a method comprising directing the tool along a call tool path.

According to another preferred embodiment of the present invention, an automated computer-implemented device for generating instructions for controlling a computer numerical control machine for manufacturing an article from a workpiece, the cross-sectional area of the desired article to be manufactured from the workpiece, Forming separate regions of the cross-section on the workpiece surface that will not be removed as islands, initiating the establishment of a tool path in an area without islands, and when the island and tool path meet, Further provided is an apparatus comprising a tool routing engine operative to set a call tool path to form.

Advantageously, said set engine forms a composite region comprising said island, an arc surrounding said island, and regions that have already been removed from said workpiece as removed regions, and including said removed regions. And to set a tool path to remove remaining areas of the workpiece that are not.

Advantageously, said setting engine also selects a maximum allowable engagement angle between a tool and said workpiece, selects a minimum allowable engagement angle between said tool and said workpiece, and said engagement angle is said maximum allowable engagement angle. And set the arc tool path for the workpiece to cause a gradual change between and the minimum allowable engagement angle.

Advantageously, in response to consideration of at least one of the characteristics of the computer numerical control machine, the rotary cutting tool, and the workpiece material, the setting step also applies a different constraint, with the rate of change of the engagement angle over time. Minimizing the number of steps; gradually varying the feed rate of the tool in response to the varying engagement angle, maintaining an overall constant workload for the tool, and minimizing the manufacturing cost of the article. Whereby the cost is a combination of the cost of operating the machine during the period of manufacture and the wear cost imposed on the tool during the period of manufacture.

Additionally, the tool path includes a plurality of tool path segments, and the tool path setting includes recursively setting each of the tool path segments, wherein the computer numerical control machine, the rotary cutting tool and the In response to taking into account at least one of the properties of the material of the workpiece, setting each of the tool path segments also minimizes the rate of change of the engagement angle over time, while applying other constraints. Gradually changing a feed rate of the tool in response to an engagement angle, maintaining an overall constant work load for the tool, and minimizing the cost of machining each of the tool path segments; Whereby the cost is the ratio of operating the machine during the period of machining. And wear costs imposed on the tool during the machining period.

Additionally, each of the tool path segments includes a plurality of tool path subsegments, and recursively setting each of the tool path segments includes recursively setting each of the tool path subsegments; Wherein, in response to taking into account at least one of the computer numerical control machine, the rotary cutting tool and the properties of the material of the workpiece, the step of setting each of the tool path subsegments may also be performed by applying different constraints. Minimizing a rate of change of the engagement angle in accordance with the method, gradually changing a feed rate of the tool in response to the changing engagement angle, maintaining an overall constant work load for the tool, and the tool path sub Minimizing the cost of machining each of the segments, and Thereby the cost is a combination of the cost of operating the machine during the period of machining and the wear cost imposed on the tool during the period of machining.

According to another preferred embodiment of the invention, an automated computer controlled machine for manufacturing an article from a workpiece, taking into account the cross-sectional area of the desired article to be manufactured from the workpiece, the cross section on the workpiece surface not to be removed as an island The tool is formed along a tool path that forms separate regions of, first directs the tool along a tool path within an island-free area, and forms an arc surrounding the island when the island and tool path meet. A machine is further provided comprising a controller operative to direct.

According to another preferred embodiment of the present invention, in consideration of the cross section of the desired article to be manufactured from the workpiece, and forming separate regions of the cross section on the workpiece surface that will not be removed as islands, within the region without islands From a workpiece machined using a computer controlled machine tool by first orienting the tool along a tool path of and directing the tool along a tool path that forms an arc surrounding the island when the island and tool path meet. More things are manufactured.

In accordance with another preferred embodiment of the present invention, there is provided an automated computer implemented method for generating instructions for controlling a computer numerical control machine to manufacture an article from the workpiece by removing portions of the workpiece that will not be included in the article. The first machining time required to remove the area is determined by removing the separation channel and removing the two independent areas by means of a rotary cutting tool between the two independent areas. Identifying at least one open area that is longer than the second machining time required to divide it into, and forming in the area at least one separation channel extending between two points on an edge of an outer boundary of the area To divide the region into at least two independent regions. This method is further provided.

Advantageously, the method also includes establishing at least one trocoid-like tool path for said rotary cutting tool in a separation channel that is removed by a tool moving along the trocoid-like tool path.

Preferably, the method further comprises selecting a maximum allowable engagement angle between the rotary cutting tool and the workpiece, selecting a minimum allowable engagement angle between the rotary cutting tool and the workpiece, and wherein the engagement angle is Establishing the at least one trocoided tool path for the workpiece to cause a gradual change between the maximum allowable engagement angle and the minimum allowable engagement angle.

In addition, in response to consideration of at least one of the characteristics of the computer numerical control machine, the rotary cutting tool, and the workpiece material, the setting step also applies a rate of change of the engagement angle over time, while applying other constraints. Minimizing, gradually changing a feed rate of the tool in response to the varying engagement angle, maintaining an overall constant work load for the tool, and minimizing the manufacturing cost of the article; Whereby the cost is a combination of the cost of operating the machine during the period of manufacture and the wear cost imposed on the tool during the period of manufacture.

Advantageously, said at least one trocoid-type tool path includes a plurality of trocoid-type tool path segments, and at least one trocoid-type tool path setting step includes recursively setting each of said trocoid-type tool path segments. Wherein, in response to taking into account at least one of a computer numerical control machine, a rotary cutting tool, and the properties of the material of the workpiece, setting each of the tool path segments also applies other constraints, Minimizing the rate of change of the engagement angle over time, gradually changing the feed rate of the tool in response to the changing engagement angle, maintaining an overall constant workload for the tool, and the tool path To minimize the cost of machining each of the segments Including type, and thus the cost is by a combination of wear costs exerted on the tool while the machine cost and the machining period for operating for the duration of the machining.

Additionally, each of the tool path segments includes a plurality of tool path subsegments, and recursively setting each of the tool path segments includes recursively setting each of the tool path subsegments; Wherein, in response to taking into account at least one of the computer numerical control machine, the rotary cutting tool and the properties of the material of the workpiece, the step of setting each of the tool path subsegments may also be performed by applying different constraints. Minimizing a rate of change of the engagement angle in accordance with the method, gradually changing a feed rate of the tool in response to the changing engagement angle, maintaining an overall constant work load for the tool, and the tool path sub Minimizing the cost of machining each of the segments, and Thereby the cost is a combination of the cost of operating the machine during the period of machining and the wear cost imposed on the tool during the period of machining.

According to another preferred embodiment of the present invention, a method for machining a workpiece by employing a computer controlled machine tool, wherein the first machining time required to remove a zone is rotated between two independent zones. Identifying at least one open area longer than a second machining time required to divide the area into the two independent areas by removing the separation channel and removing the two independent areas by a cutting tool. Dividing the region into at least two independent regions by directing the tool along a trocoid-like tool path in at least one separation channel extending between two points on an edge of an outer boundary of the region. Further provided is a method comprising the steps of:

According to another preferred embodiment of the present invention, there is provided an automated computer implemented device for generating instructions for controlling a computer numerical control machine for manufacturing an object from the workpiece by removing portions of the workpiece that will not be included in the object. The first machining time required to remove the zone is determined by removing the separation channel by the rotary cutting tool between the two independent zones and removing the two independent zones. Identify at least one open area that is longer than the second machining time required to split it into two, and form at least one separation channel in the area extending between two points on the edge of the outer boundary of the area To divide the region into at least two independent regions. The device containing the setting to the engine is further provided.

Advantageously, said tool routing engine is further operable to set at least one trocoid-like tool path for said rotary cutting tool in said separation channel removed by said tool moving along the trocoid-like tool path.

Further, the setting step includes selecting a maximum allowable engagement angle between the rotary cutting tool and the workpiece, selecting a minimum allowable engagement angle between the rotary cutting tool and the workpiece, and wherein the engagement angle is Establishing the at least one trocoided tool path for the workpiece to cause a gradual change between a maximum allowable engagement angle and the minimum allowable engagement angle.

In addition, in response to consideration of at least one of the characteristics of the computer numerical control machine, the rotary cutting tool and the workpiece material, setting each of the tool path segments may also be performed over time, while applying other constraints. Minimizing the rate of change of the engagement angle, gradually changing the feed rate of the tool in response to the changing engagement angle, maintaining an overall constant workload for the tool, and manufacturing costs of the article Minimizing, whereby the cost is a combination of the cost of operating the machine during the period of manufacture and the cost of wear applied to the tool during the period of manufacture.

Further, the at least one trocoid-type tool path includes a plurality of trocoid-type tool path segments, and the at least one trocoid-type tool path setting step includes recursively setting each of the trocoid-type tool path segments. And in response to taking into account at least one of the computer numerical control machine, the rotary cutting tool, and the properties of the material of the workpiece, the step of setting each of the tool path segments also takes time, taking into account other constraints. Minimizing a rate of change of the engagement angle in accordance with the method, gradually changing a feed rate of the tool in response to the changing engagement angle, maintaining an overall constant workload for the tool, and the tool path segment To minimize the cost of machining each of the Hereinafter, and thus the cost is by the combination of the applied wear costs for the cost and the tool during the machining period for operating the machine for the duration of the machining.

Additionally, each of the tool path segments includes a plurality of tool path subsegments, and recursively setting each of the tool path segments includes recursively setting each of the tool path subsegments; Wherein, in response to taking into account at least one of the computer numerical control machine, the rotary cutting tool and the properties of the material of the workpiece, the step of setting each of the tool path subsegments may also be performed by applying different constraints. Minimizing a rate of change of the engagement angle in accordance with the method, gradually changing a feed rate of the tool in response to the changing engagement angle, maintaining an overall constant work load for the tool, and the tool path sub Minimizing the cost of machining each of the segments, and Thereby the cost is a combination of the cost of operating the machine during the period of machining and the wear cost imposed on the tool during the period of machining.

According to another preferred embodiment of the present invention, an automated computer controlled machine for manufacturing an article from a workpiece, wherein the first machining time required to remove the zone is a rotary cutting tool between two independent zones. Identify at least one open region longer than the second machining time required to divide the region into the two independent regions by removing the separation channel and removing the two independent regions, and Directing the tool along at least one trocoid-like tool path in at least one separation channel extending between two points on the edge of the outer boundary of the region to divide the region into at least two independent regions. There is further provided a machine including a operative controller.

According to another preferred embodiment of the present invention, the first machining time required to remove the area removes the separation channel by the rotary cutting tool between the two independent areas and removes the two independent areas. Thereby identifying at least one open area that is longer than a second machining time needed to divide the area into two independent areas, and extending between two points on an edge of an outer boundary of the area. Further provided is an article made from a workpiece machined using a computer controlled machine tool by forming at least one separation channel in the region, dividing the region into at least two independent regions.

Preferably, the article is manufactured by directing the rotary cutting tool along at least one trocoid-like tool path in the separation channel that is removed by a tool moving along the trocoid-like tool path.

In accordance with another preferred embodiment of the present invention, there is provided an automated computer implemented method for generating instructions for controlling a computer numerical control machine to manufacture an article from the workpiece by removing portions of the workpiece not included in the article. The first machining time required to remove the area by employing a trocoid-type tool path removes the area by removing the separation channels between the area and all closed outer boundary segments of the area and removing the remainder of the area. Identifying at least one semi-open area longer than the second machining time required to isolate, and forming at least one separation channel between said area and all closed outer boundary segments of said area to be removed; Forming a remaining open area to be removed Is further provided.

Advantageously, the method also includes establishing at least one trocoid-like tool path for said rotary cutting tool in said separation channel removed by a tool moving along said at least one trocoid-like tool path.

Preferably, the method further comprises selecting a maximum allowable engagement angle between the rotary cutting tool and the workpiece, selecting a minimum allowable engagement angle between the rotary cutting tool and the workpiece, and wherein the engagement angle is Establishing the at least one trocoided tool path for the workpiece to cause a gradual change between the maximum allowable engagement angle and the minimum allowable engagement angle.

In addition, in response to consideration of at least one of the characteristics of the computer numerical control machine, the rotary cutting tool, and the workpiece material, the setting step also applies a rate of change of the engagement angle over time, while applying other constraints. Minimizing, gradually changing a feed rate of the tool in response to the varying engagement angle, maintaining an overall constant work load for the tool, and minimizing the manufacturing cost of the article; Whereby the cost is a combination of the cost of operating the machine during the period of manufacture and the wear cost imposed on the tool during the period of manufacture.

Advantageously, said at least one trocoid-type tool path includes a plurality of trocoid-type tool path segments, and at least one trocoid-type tool path setting step includes recursively setting each of said trocoid-type tool path segments. Wherein, in response to taking into account at least one of a computer numerical control machine, a rotary cutting tool, and the properties of the material of the workpiece, setting each of the tool path segments also applies other constraints, Minimizing the rate of change of the engagement angle over time, gradually changing the feed rate of the tool in response to the changing engagement angle, maintaining an overall constant workload for the tool, and the tool path To minimize the cost of machining each of the segments Including type, and thus the cost is by a combination of wear costs exerted on the tool while the machine cost and the machining period for operating for the duration of the machining.

Additionally, each of the tool path segments includes a plurality of tool path subsegments, and recursively setting each of the tool path segments includes recursively setting each of the tool path subsegments; Wherein, in response to taking into account at least one of the computer numerical control machine, the rotary cutting tool and the properties of the material of the workpiece, the step of setting each of the tool path subsegments may also be performed by applying different constraints. Minimizing a rate of change of the engagement angle in accordance with the method, gradually changing a feed rate of the tool in response to the changing engagement angle, maintaining an overall constant work load for the tool, and the tool path sub Minimizing the cost of machining each of the segments, and Thereby the cost is a combination of the cost of operating the machine during the period of machining and the wear cost imposed on the tool during the period of machining.

According to another preferred embodiment of the present invention, a method for machining a workpiece by employing a computer controlled machine tool, wherein the first machining time required to remove the area by employing a trocoid-type tool path is the area. Identifying at least one semi-open area that is longer than a second machining time required to isolate the area by removing separation channels between all closed outer boundary segments of the area and removing the remaining portion of the area, And forming at least one separation channel between the region and all closed outer boundary segments of the region in the region to be removed, thereby forming the remaining open region to be removed.

In accordance with another preferred embodiment of the present invention, there is provided an automated computer implemented device for generating instructions for controlling a computer numerical control machine to manufacture an article from the workpiece by removing portions of the workpiece that are not included in the article. The first machining time required to remove the area by employing a trocoid-type tool path removes the area by removing the separation channels between the area and all closed outer boundary segments of the area and removing the remainder of the area. Identifying at least one semi-open area longer than the second machining time required to isolate, and forming at least one separation channel between said area and all closed outer boundary segments of said area to be removed, A tool operative to form the remaining open area to be removed A device is further provided comprising a routing engine.

Advantageously, said tool routing engine also operates to establish at least one trocoid-like tool path for said rotary cutting tool in said separation channel removed by said tool moving along the trocoid-like tool path.

Advantageously, the setting step includes selecting a maximum allowable engagement angle between the rotary cutting tool and the workpiece, selecting a minimum allowable engagement angle between the rotary cutting tool and the workpiece, and wherein the engagement angle is Establishing the at least one trocoided tool path for the workpiece to cause a gradual change between the maximum allowable engagement angle and the minimum allowable engagement angle.

Preferably, in response to taking into account at least one of the computer numerical control machine, the rotary cutting tool, and the properties of the material of the workpiece, the step of setting each of the tool path segments may also be time-dependent while applying other constraints. Minimizing a rate of change of the engagement angle in accordance with the method, gradually changing a feed rate of the tool in response to the changing engagement angle, maintaining a generally constant workload for the tool, and manufacturing the article Minimizing the cost of doing so, wherein the cost is a combination of the cost of operating the machine during the period of manufacture and the wear cost imposed on the tool during the manufacture.

Further, the at least one trocoid-type tool path includes a plurality of trocoid-type tool path segments, and the at least one trocoid-type tool path setting step includes recursively setting each of the trocoid-type tool path segments. And in response to taking into account at least one of the computer numerical control machine, the rotary cutting tool, and the properties of the material of the workpiece, the step of setting each of the tool path segments also includes time, while applying other constraints. Minimizing a rate of change of the engagement angle in accordance with the method, gradually changing a feed rate of the tool in response to the changing engagement angle, maintaining an overall constant workload for the tool, and the tool path segment To minimize the cost of machining each of the Hereinafter, and thus the cost is by a combination of the applied wear costs for the cost and the tool during the machining operation of the machine for the duration of the machining.

Additionally, each of the tool path segments includes a plurality of tool path subsegments, and recursively setting each of the tool path segments includes recursively setting each of the tool path subsegments; Wherein, in response to taking into account at least one of the computer numerical control machine, the rotary cutting tool and the properties of the material of the workpiece, the step of setting each of the tool path subsegments may also be performed by applying different constraints. Minimizing a rate of change of the engagement angle in accordance with the method, gradually changing a feed rate of the tool in response to the changing engagement angle, maintaining an overall constant work load for the tool, and the tool path sub Minimizing the cost of machining each of the segments, and Thereby the cost is a combination of the cost of operating the machine during the period of machining and the wear cost imposed on the tool during the machining.

According to another preferred embodiment of the present invention, an automated computer controlled machine for manufacturing an object from a workpiece, the first machining time required to remove the area by employing a trocoid-type tool path is such that the area and the Identify at least one semi-open area that is longer than a second machining time required to isolate the area by removing separation channels between all closed outer boundary segments of the area and removing the remaining portion of the area, and the area And a controller further operable to direct the tool along the trocoid-like tool path in at least one separation channel between all closed outer boundary segments of the region to form the remaining open region to be removed.

According to another preferred embodiment of the present invention, the first machining time required to remove an area by employing a trocoid-type tool path eliminates the separation channels between the area and all closed outer boundary segments of the area and Identify at least one semi-open area that is longer than the second machining time required to isolate the area by removing a residual portion of the at least one, and at least one separation channel between the area and all closed outer boundary segments of the area There is further provided an article made from a workpiece machined using a computer controlled machine tool by forming an in said area to be removed, thereby forming the remaining open area to be removed.

Preferably, the article is also manufactured by directing the rotary cutting tool along at least one trocoid-like tool in the separation channel removed by the tool moving along the trocoid-like tool path.

The invention will be more fully understood from the following detailed description taken in conjunction with the drawings.
1A-1S-2 are a series of simplified illustrations to help understand the present invention;
2A-2L-2 are another series of simplified illustrations to help understand the present invention;
3A-3D are simplified screen shots illustrating some aspects of the present invention;
4A and 4B are simplified illustrations of the details of the functions more generally illustrated in certain of FIGS. 1A-1S-2 and 2A-2L-s.

The present invention relates to various aspects of an automated computer implemented method for generating instructions for controlling a computer numerical control (CNC) machine to manufacture an article from a stock material, a method for machining a raw material employing the instructions, said An automated computer-implemented device for generating instructions, a numerical control machine operative to produce articles from raw materials using the instructions, and various aspects of articles manufactured using the instructions.

The invention, in its various aspects, is described below with respect to a series of drawings, which are first produced by an example of an article to be manufactured, a simulated overlay of the article on the raw material to be machined, and the instructions generated according to the present invention. Describe the sequence of machining steps. Although the sequential machining steps are illustrated, the invention is not limited to the machining method, but extends to the instructions, the apparatus for generating them, and the apparatus for executing them and producing the results produced by them as described above.

The term “operation” is used throughout to refer to the generation of instructions that yield sequential machining steps to be employed in the machining of a particular area of raw material. The definitions and operations of "operate", "operation" have a corresponding meaning.

1A and 1B are illustrations of respective views and top views of an article 100 that is an example of an article that may be made in accordance with the present invention. The setting of the article 100 is selected to illustrate various specific features of the present invention. Note that any suitable three-dimensional article that can be machined by conventional three-axis CNC machine tools can be manufactured according to a preferred embodiment of the present invention.

As shown in FIGS. 1A and 1B, the article 100 has a generally flat base portion 102 with five protrusions extending, which are designated by reference numerals 104, 106, 108, 110, and 112 in the text. It is shown to have. 1C shows the raw material 114 overlaid by the outline of the article 100.

In accordance with a preferred embodiment of the present invention, using an automated computer-implemented method of generating instructions to control the computer numerical control machine of the present invention, the tool path designer can designate the CAD of the object 100 in a standard CAD format such as SOLIDWORKS®. Access the drawing. The designer selects a particular machine tool from the menu to be used for the manufacture of the article 100 and selects a particular rotary cutting tool to perform each machining function required to manufacture the article.

For simplicity, the illustrated article 100 is selected to be an article that can be manufactured by a single machining function, and it is understood that the applicability of the present invention is not limited to an article that can be manufactured by a single machining function. Will be.

The tool path designer then forms the geometry of the raw material to be used in the manufacture of the article 100. This can be done automatically by the automated computer implemented device of the present invention or manually by a tool path designer. The toolpath designer then specifies the materials that make up the raw material, for example INCONEL® 718. The present invention utilizes the selection of mechanical tools, rotary cutting tools, and materials by tool path designers to calculate various operating parameters based on the machine tools, rotary cutting tools, and material properties.

According to a preferred embodiment of the present invention, a series of display screens have a minimum and maximum surface cutting speed, a minimum and maximum chip thickness, a minimum and maximum feed speed, a minimum and maximum spindle rotation speed, a minimum between a rotary cutting tool and a workpiece and It is employed to provide a tool path designer with a display that shows various operating parameters such as maximum engagement angle, cutting depth of the axis, level of machining agressiveness. An example of such a series of display screens is shown in FIGS. 3A-3D.

Tool path designers are given latitude, especially in changes in some parameters, such as machining advance levels. Preferably, the tool path designer also instructs the system to select, for example, optimized machining time, degree of wear applied to the cutting tool, machining cost or a combination thereof. While a range of values has been displayed in the tool path designer for some of the operating parameters described above, it will be appreciated that the present invention also calculates optimal operating values for all operating parameters to be employed.

Once all the parameters appearing on the screen, such as the display screen of FIGS. 3A-3D, are finalized, a tool path for machining the workpiece is computed in accordance with a preferred embodiment of the present invention. The calculation of the tool path according to a preferred embodiment of the present invention is described below with reference to FIGS. 1A-1S-2 illustrating the actual progress of the tool path in raw material 114.

The tool path is computed recursively so that the first tool path segment of the tool path is computed for the first area of the workpiece, then the subsequent sequential tool path segment of the tool path is the first area of the remaining area of the workpiece. It is a particular feature of the present invention that is similarly computed for. Additional subsequent sequential tool path segments are similarly computed until a tool path for machining the entire workpiece for the desired object is calculated.

First, a first cross section of a raw material having an outline of the article 100 superimposed thereon and having a depth equal to the designated cutting axis depth is calculated. This cross section is schematically illustrated in FIG. 1D and designated by reference numeral 116. Cross section 116 includes a plurality of islands 105, 107, 109, 111, and 113 corresponding to the cross sections of protrusions 104, 106, 108, 110, and 112, respectively, at a depth of cross section 116. It is characterized by having a boundary (118). The islands 105, 107, 109, 111, and 113 are generally offset outward with respect to the cross section of the protrusions 104, 106, 108, 110, and 112 by a distance slightly larger than the radius of the rotary cutting tool, thereby surrounding the islands. It will be appreciated that when machining the tool path, the narrow finish width remains to be machined last in a later step.

It will be appreciated that the axial depth of cross section 116 constitutes a first step down, which is the first phase in the machining of article 100. Overall, the term "step down" is used to describe a single machining phase at a constant depth. As shown in FIG. 1C, the completion of machining of the article 100 requires two additional step downs corresponding to the cross sections 119, 120. Therefore, following the calculation of the cross section 116, the second step down corresponding to the cross sections 119 and 120 and the third step down thereafter are calculated. Preferably, the vertical distance between subsequent step downs is generally 1 to 4 times the diameter of the rotary cutting tool.

According to a preferred embodiment of the present invention, the machining area is first automatically identified in cross section 116. There are three types of machining zones which are preferably classified by the nature of their outer boundaries. Overall, the segment of the boundary of the area where the area can be reached by the rotary cutting tool from outside of the area by the horizontal advancement of the rotary cutting tool is called an "open edge." All other boundary segments are referred to collectively as "closed edges."

The three types of machining areas are classified as follows:

An open region, wherein the entire outer boundary of the type I-region consists only of open edges;

A semi-open region, characterized in that the outer boundary of the type II-region consists of both open and closed edges;

A closed region, wherein the entire outer boundary of the type III-region consists only of closed edges;

Preferably, the tool path to be employed when machining the area is calculated to include one or more tool path segments, where each tool path segment is a converging spiral tool path segment, a trocoid-like tool path segment and a diverging spiral tool path segment. Is one of. In general, converging helix tool path segments are preferred when machining Type I regions, trocoded tool path segments are preferred when machining Type II regions, and diverging helix tool path segments are preferred when machining Type III regions. desirable.

The term "trocoid-like" is used to mean a trocoid-like tool path or its modulation that maintains a curved cutting path and a return path that may be curved or entirely straight.

As is known to those skilled in the art, the machining of spiral tool path segments is generally more efficient with respect to the amount of material removed per unit time than the machining of trocoided tool path segments for similar average step over. Accordingly, the present invention seeks to maximize the area to be machined by the spiral tool path segment.

The converging spiral tool path segment computed to machine the type I region is preferably a tool path segment that spirals inward from the outer boundary of the region to the inner contour. The inner contour is preferably calculated as follows:

If there is no island in the outer boundary of the type I region, the inner contour is preferably calculated such that the radius as a whole is smaller than the radius of the cutting tool and is a small circle centered around the center of the area of the region;

If there is one island within the outer boundary of the type I region and the shortest distance between one island and the outer boundary of the region of type I is longer than the selected ratio of the diameter of the rotary cutting tool, then the inner contour is preferably totally island. Computed along the outer boundary of; And

There is one island within the outer boundary of the type I region and the shortest distance between the single island and the outer boundary of the type I region is shorter than the selected ratio of the diameter of the rotary cutting tool; or

If there is more than one island within the outer boundary of the type I area,

The inner contour is preferably calculated to be an outline offset internally with respect to the outer boundary of the area by a distance as a whole a distance equal to 1.5 times the radius of the rotary cutting tool.

Once the inner contours are computed, it is automatically proved that the inner contours do not self cross. If the inner contours cross at one or more locations, the bottleneck is preferably identified near each such self intersection. If the bottleneck does not overlap with the island, then separate channels are preferably calculated at each such bottleneck. The separating channel preferably divides the region into two Type I regions which can be machined independently of each other by individual converging spiral tool path segments. If the bottleneck overlaps the island, the inner contour is preferably recomputed to be offset internally towards the outer boundary, preferably by half of the original offset. This process is repeated until an internal contour that is not self-crossing is computed.

It is a particular feature of the invention that the converging helix tool path segment that spirals inwards from the outer boundary of the region to the inner contour is computed to be a “morphing helix”. The term "morphing helix" is used to mean a helix tool path segment which, as a whole, a helix tool path segment helix that gradually morphs the geometry of one boundary or contour into the geometry of a second boundary or contour. While various morphing methods are known to those skilled in the art, the present invention seeks to implement certain morphing methods in accordance with preferred embodiments of the present invention as described below.

It is another feature of the present invention that the engagement angle of the cutting tool employed throughout the tool path segment is not fixed and varies between a predetermined minimum and maximum engagement angle on the course of the tool path segment. This change in engagement angle allows for varying stepover on the course of the tool path segment, allowing the tool path segment to morph between two dissimilar geometries. The term "stepover" is used to designate the distance between sequential loops of a spiral tool path segment as a whole. It will be appreciated that the cutting tool efficiency achieved by employing a morphing spiral tool path segment is generally significantly greater than the cutting exit efficiency achieved by employing a trocoid-type tool path segment. It will also be appreciated that, where appropriate, an engagement angle as a whole close to the maximum engagement angle is desirable.

While employing varying engagement angles over the course of the tool path segment has a negative effect of increasing wear of the cutting tool due to varying mechanical loads and thinning of the chip on the cutting tool, this negative effect generally It is a particular feature of the present invention that it is compensated by automatically and dynamically adjusting the feed rate to correspond to changing engagement angles. Another feature of the present invention is that the engagement angle is gradually changed over the course of the tool path segment to prevent sharp and steep changes in the cutting tool rod, thereby further reducing excessive wear of the cutting tool.

Returning to the calculation of the converging spiral tool path segment employed to machine the region of type I, once the inner contour is computed, the loop to be included in the converging spiral tool path segment that spirals inward from the outer boundary of the region to the inner contour. The number of is preferably calculated as shown in FIG. 4A.

As shown in FIG. 4A, a plurality of bridges 500 of predefined density are each stretched from the inner contour 502 to the outer boundary 504. The bridge point 506 of each bridge 500 is first formed as an intersection point of the bridge 500 with the outer boundary 504. The length of the shortest bridge divided by the minimum stepover is generally equal to the maximum number of loops that can be included in the spiral tool path segment. The length of the longest bridge divided by the maximum stepover is generally equal to the minimum number of loops that must be included in the spiral tool path. As mentioned above, the minimum and maximum engagement angles are determined based on information provided by the tool path designer, which angles determine the minimum and maximum stepover of the spiral tool path segment.

In any direction, it will be understood that the furthest distance from the inner contour 502 that can be machined by the converging spiral tool path segment is the number of loops included in the converging spiral tool path segment multiplied by the maximum stepover. The area between the inner contour 502 and the outer boundary 504 farthest away from the inner contour cannot be machined by the converging spiral tool path segment, and therefore preferably prior to machining of the converging spiral tool path segment. It is machined by clipping. Overall, the term "clipping" is used to define the calculation of the machining of the area of the area that cannot be machined by the optimal spiral tool path segment. In general, the clipped area is individually machined by a trocoded tool path segment prior to the machining of the spiral tool path segment, or by a separate channel that separates the clipped area from the rest of the area and subsequently by the spiral tool path segment. It is machined by machining the clipped area separated by

Overall, the parameter 'n' is used to specify the possible number of loops to be included in the spiral tool path segment, where n is the minimum number of loops to be included in the spiral tool path segment and the maximum number of loops that can be included in the spiral tool path segment. Is the number between.

For each possible value of n, the first working time for the first machining method required to machine the area between the outer boundary 504 and the inner contour 502 is determined by the outer boundary as described below. Computed by adding the time required to machine all clipped areas identified between 504 and internal contour 502 with the time required to machine the spiral tool path segment. The optimal number of loops to be included in the spiral tool path segment is selected such that the first calculated working time is the value of n, the shortest time.

If the inner contour is calculated to be a small circle centered around the center of the area of the area, the second working time for the second machining method extends along the shortest bridge connecting the outer boundary to the inner contour, and further The working time required to machine the separation channel extending through the small circle and then extending along the opposite bridge to the opposite segment of the outer boundary, dividing the region into two independent Type I regions; Calculated by summing up the work time required to machine two independent Type I areas. If the second working time is shorter than the first working time, the second machining method is preferred over the first machining method.

Once the optimal number of loops to be included in the converging spiral tool path segment is selected, the clipped area and the tool path for its removal are computed as described above. As a result, a new outer boundary formed by the clipped area is computed and all bridge points are updated accordingly to be located on the new outer boundary. Then, the actual path of the spiral tool path segment is calculated as follows:

First, the bridge point 510 of the first bridge 512 is preferably selected as the first helix point of the helix tool path segment 514. The first bridge 512 is preferably selected to minimize the time required to move the cutting tool from its previous position. The second possible spiral point of the spiral tool path segment 514 is computed from the first bridge 512 as a point on the second bridge 516 immediately adjacent the first bridge 512 in the climbing direction of the cutting tool and The point is spaced apart from the bridge point 517 of the second bridge 516 along the second bridge 516 by the length of the second bridge 516 divided by the remaining number of loops to be included in the tool path segment 514. do.

For a possible second helix point, the engagement angle that engages the material is calculated by the cutting tool following the helix tool path segment 514 from the first helix point 510 to the second possible helix point. If the calculated engagement angle is between a predetermined minimum and maximum engagement angle, a second spiral point possible as the second spiral point 518 is selected, and between the first spiral point 510 and the second spiral point 518. A new linear subsegment 520 is added to the spiral tool path segment 514.

If the engagement angle is less than the predetermined minimum engagement angle, a binary search is performed for the second helix point where the calculated engagement angle is equal to the overall predetermined minimum engagement angle. The differentiation search is performed between the possible second helix point and the point on the second bridge 516 spaced apart from the bridge point 517 of the second bridge 516 by the maximum stepover. If a second helix point is found, a new linear subsegment 520 between the first helix point 510 and the second helix point 518 is added to the helix tool path segment 514.

If the engagement angle is greater than the predetermined maximum engagement angle, then a dichotomous search for a second helix point is performed such that the calculated engagement angle as a whole is a predetermined maximum engagement angle. The differentiation search is performed between the bridge point 517 of the second bridge 516 and the possible second helix point. If the second helix point 518 is found, a new linear subsegment 520 between the first helix point 510 and the second helix point 518 is added to the helix tool path segment 514.

When the new linear subsegment 520 intersects the inner contour 502 of the region, the spiral tool path segment 514 creates one or more individual unmachined residual areas that are generally adjacent to the inner contour 502, Terminate at the intersection point. For each individual residual area, if the size of the individual residual area is larger than a predetermined small value, it is calculated to be machined by the trocoid-type tool path segment.

When the new linear subsegment 520 intersects the island, the computation of the spiral tool path segment 514 terminates at the intersection point, and the moat is computed to start at the intersection point and surround the island. The remaining areas for which the tool path has already been calculated are designated as new type I areas to be calculated individually.

The term "arc" is used to designate a trocooid-type tool path segment that encloses the island as a whole, machining a channel adjacent to the island as a whole, separating the island from the remaining materials that need to be machined. The width of the arc is preferably at least 2.5 times the radius of the cutting tool and most preferably 4 times the radius of the cutting tool. While these values are predetermined, these values can be changed by the tool path designer. It is a particular feature of the invention that machining the arc around the island operates to produce residual areas of the same type as the original areas. This is therefore a specific value when machining a Type I area or Type III area that can be machined entirely by a spiral tool path segment which is generally more efficient than a trocoid type tool path segment.

In addition, machining an arc to surround the island is effective to prevent the formation of two fronts of the machined area adjacent to the island. As is known to those skilled in the art, the formation of narrow residual walls is undesirable because machining them may cause damage to the cutting tool and / or the workpiece.

Once the second helix point 518 is computed, the remaining number of loops to be included in the remainder of the tool path segment 514 is updated. It will be appreciated that the remaining number of loops can be a mixed number. Subsequent segments of the remainder of the spiral tool path segment 514 are recursively computed to determine a second spiral point 518 that will be the new first point of the remainder of the spiral tool path segment 514 and A bridge 530 is defined immediately adjacent to the second bridge 516 in the upward direction of the cutting tool from the second bridge 516 to be the second bridge. In addition, the second helix point 518 is defined as the new bridge point of the second bridge 516, and the remaining area to be machined is recomputed.

Machining in the type II area is calculated as follows:

First, the machining time required to machine the separate channels adjacent to all closed edges of the type II area and the machining time required to machine the remaining area of the area by the converging spiral tool path segment. Is computed. In addition, the trocoid type machining time is calculated as the machining time required to machine the entire type II area by the trocoid type tool path segment. If the spiral machining time is shorter than the trocoid type machining time, a separate channel adjacent to all closed edges of the area is calculated, and the remaining separated area to be machined by the converging spiral tool path segment is calculated. If the spiral machining time is longer than the trocoid machining time, the trocoid tool path segment is calculated as follows:

As the "front" of the region, the longest open edge of the region is selected. The rest of the outer boundary of the area is formed as a "blocking boundary". The starting end is selected as one of the two ends of the front face, which results in a climb milling tool path during machining along the front face from the starting end to the opposite end.

As shown in FIG. 4B, a plurality of bridge lines 550 of predefined density are each stretched from the front surface 552 toward the blocking boundary 554 across the region. The bridge point 556 of each bridge 550 is first formed as each intersection point of the bridge 550 with the front surface 552. The end 562 opposite the start end 56 is selected such that the bridge 550 is ordered from the start end to the opposite end 562 in the upward direction of the cutting tool. A single open trocoid-shaped tool path segment 564 for machining an area adjacent to the front face 552 having a width equal to the maximum stepover as a whole selects an appropriate point on each bridge 55 and starts the appropriate points. By crossing in the order of the bridge lines between 560 and the opposite ends 562, it is calculated as follows:

First, the starting end 560 is preferably selected as the first point of the single trocoid-shaped tool path segment 564. The second possible point of the trocoded tool path segment 564 is computed from the first point 560 as a point on the first bridge 570 immediately adjacent the first point 560 in the climbing direction of the cutting tool and The second possible point is spaced apart from the bridge point 572 of the first bridge by the greater of the maximum stepover and the length of the first bridge 570. In the illustrated example of FIG. 4B, a possible second point is computed to be at the intersection 574 of the first bridge 572 and the blocking boundary 554.

For a second possible point, the engagement angle that engages the material is calculated by the cutting tool following the cutting tool path from the first point to the second possible point. If the calculated engagement angle is between a predetermined minimum and maximum engagement angle, the second point possible as the second point is selected, and a new linear subsegment between the first point 560 and the second point is a single trocoid cut. Is added to the tool path segment 564.

If the engagement angle is smaller than the predetermined minimum engagement angle, a dichotomous search for the second point is performed where the calculated engagement angle is equal to the overall predetermined minimum engagement angle. The differentiation search is spaced apart from the bridge point 572 of the first bridge 570, along the first bridge 570, by the greater of the possible second point and maximum stepover and the length of the first bridge 570. Between the points on the first bridge 570. If a second point is found, a new linear subsegment between the first point 560 and the second point is added to the single trocoid-shaped cutting tool path segment 564.

If the engagement angle is greater than the predetermined maximum engagement angle, a dichotomous search for the second point is performed where the calculated engagement angle is equal to the overall predetermined maximum engagement angle. The differentiation search is performed between the bridge point 572 of the first bridge 570 and the possible second point. If a second point is found, a new linear subsegment between the first point 560 and the second point is added to the single trocoid-shaped cutting tool path segment 564.

In the example shown in FIG. 4B, the intersection point 564 is selected as the second point, and a new linear subsegment 580 between the first point 560 and the second point 574 is a single trocoid-type cutting tool path segment. 564 is added.

As a result, the computation of the remainder of the single trocoded tool path segment 564 details the tool path subsegment passing through the appropriate points on the bridged 550, which is sequenced up to the opposing end 562 of the selected front face 552. This is accomplished by performing one operation recursively. If a single trocoid-like tool path segment 564 traverses an island, the single trocoid-shaped tool path segment 564 is clipped at the intersection of the single trocoid-shaped path segment 564 and the island's outer boundary, such that Create two separate subsegments of the path segment 564. These two subsegments are then connected along a section of the outer boundary of the island facing the front, which section is a closed edge.

The above operation completes the calculation of the tool path segment for machining a portion of the type II region. At this point, the remainder of the type II region to be machined is computed and the tool path for machining the remainder of the type II region is computed recursively as described above. It will be appreciated that machining of the remainder of the type II region requires repositioning of the cutting tool relative to the starting end of the front face of the remainder of the type II region. It will be appreciated that the repositioning technique is known to those skilled in the art.

Referring again to the calculation of the tool path for the machining of the type III region, a diverging spiral tool path is preferred when machining the type III region as described above. The diverging helix tool path segment computed to machine the type III region is a tool path segment that spirals outward from the innermost contour to the outer boundary through a number of nested inner contours. Nested internal contours are computed as follows:

The first nested inner contour is calculated to be an contour that is internally offset relative to the outer boundary of the area by a distance as a whole a distance equal to 1.5 times the radius of the cutting tool. In addition, the nested inner contour is then recursively computed inward from the first nested inner contour, with each nested inner contour corresponding to it a distance that is generally equal to 1.5 times the radius of the rotary cutting tool. It is spaced inwards at a distance from adjacent nested inner contours just outside. The last nested inner contour is computed so that for at least one point on the contour the contour has a center of area closer than 1.5 times the radius of the cutting tool. Inside the last nested inner contour, the innermost contour is calculated to be a small circle with a radius that is smaller than the radius of the cutting tool as a whole and centered around the center of the area of the last nested inner offset contour.

If the innermost contour is within the outer boundary of the island, or intersects with the outer boundary of the island, an arc surrounding the island is computed, so that the innermost contour does not intersect any other islands, The innermost contour is recalculated so that it is just outside. Note that nested inner contours that intersect the outer boundary of any island are discarded.

Once the nested inner contour is computed, the number of loops to be included in the diverging spiral tool path segment that spirals outward from the innermost contour to the last nested inner offset contour is preferably calculated as follows:

The plurality of bridge lines are stretched from the innermost contour to the next inner offset contour immediately adjacent to it. The bridge point of each bridge is first formed as the intersection point of the innermost contour and the bridge. The length of the shortest bridge divided by the minimum stepover theoretically provides a theoretical maximum of the number of loops that can be included in the diverging spiral tool path. The length of the longest bridge divided by the maximum stepover provides an absolute minimum of the number of loops that must be included in the diverging spiral path segment needed to machine the entire area between the innermost contour and the next inner offset contour. .

It will be appreciated that the longest distance in any direction from the innermost contour that can be reached by the diverging spiral tool path segment is the number of loops included in the diverging spiral tool path segment multiplied by the maximum stepover. The area between the innermost contour and the next inner offset contour that is beyond this farthest distance cannot be machined by the diverging spiral tool path segment, preferably by machining after clipping the diverging spiral tool path segment. do.

Overall, the parameter 'n' is used to specify the possible number of loops to be included in the spiral tool path segment, where n is the minimum number of loops to be included in the spiral tool path segment and the maximum number of loops that can be included in the spiral tool path segment. Is the number between.

For each possible value of n, the working time required for machining the area between the innermost contour and the next inner offset contour is identified between the innermost contour and the next inner offset contour as described above. It is computed by adding the time required to machine all clipped areas with the time required to machine the spiral tool path segment. The optimal value of the loop to be included in the spiral tool path segment is chosen such that the computed work time is the value of n, the shortest time.

When the optimal value of the loop to be included in the tool path segment is selected, the actual path of the spiral tool path segment is calculated. First, the bridge point of the first bridge is preferably selected as the starting helix point of the helix tool path segment. The first bridge is preferably selected to minimize the time required to move the rotary cutting tool from its previous position. The second possible spiral point of the spiral tool path segment is computed from the first bridge as a point on the second bridge immediately adjacent the first bridge in the climbing direction of the cutting tool, the point being the remainder of the loop to be included in the tool path segment. Spaced apart from the bridge point of the second bridge by the length of the second bridge divided by a number.

For a possible second helix point, the engagement angle that engages the material is calculated by the cutting tool following the helix tool path from the first helix point to the second possible helix point. If the calculated engagement angle is between a predetermined minimum and maximum engagement angle, the second spiral point possible as the second spiral point is selected, and a new linear subsegment between the first spiral point and the second spiral point is the spiral cutting tool. Is added to the path segment.

If the engagement angle is smaller than the predetermined minimum engagement angle, a dichotomous search for a second helix point is performed such that the calculated engagement angle as a whole is a predetermined minimum engagement angle. The differentiation search is performed between the possible second helix point and the point on the second bridge spaced from the bridge point of the second bridge by the maximum stepover. If a second helix point is found, a new linear subsegment between the first helix point and the second helix point is added to the helix tool path segment.

If the engagement angle is greater than the predetermined maximum engagement angle, then a dichotomous search for a second helix point is performed such that the calculated engagement angle as a whole is a predetermined maximum engagement angle. The differentiation search is performed between the bridge point of the second bridge and the possible second helix point. If a second helix point is found, a new linear subsegment between the first helix point and the second helix point is added to the helix tool path segment.

When the new linear subsegment intersects the island, the computation of the spiral tool path segment ends at the intersection point, where the arc begins and is calculated to surround the island. The remaining areas for which the tool path has already been calculated are designated as new type III areas to be calculated individually.

If the new linear subsegment intersects the next inner offset contour, an additional loop of diverging spiral tool path segments is computed, and the portion of the additional loop that is inner for the next inner offset contour is computed with the diverging spiral tool path segment and the next inner. One or more uncalculated residual areas between the offset contours are formed, each of which is computed as a type II region, preferably by employing a trocoded tool path segment. The portion of the additional loop that is internal to the next inner offset contour is connected along the next inner offset contour to form a continuous loop that is the last loop of the diverging helix tool path segment.

If the second helix point is computed, the remaining number of loops to be included in the tool path segment is recalculated and the subsequent segment of the helix cutting tool path segment is recursively computed to become the new point of the remainder of the helix tool path segment. The point is set and the bridge immediately adjacent to the second bridge in the upward direction of the cutting tool from the second bridge to be the new second bridge. In addition, the second helix point is defined as the new bridge point of the second bridge, and the remaining area to be machined is recomputed.

As a result, the calculation of the remainder of the diverging spiral tool path relative to the remainder of the region is performed through a diverging spiral tool through a pair of subsequent consecutive nested inner contours between the last nested inner offset contour and the outer boundary of the region. This is accomplished by performing the above operation of the path segment recursively.

It will be appreciated that all operations of the tool path described above yield a discrete linear tool path. If the discrete linear tool path is not suitable for a particular workpiece machined by a particular CNC machine, a smoothing approximation of the discrete linear tool path can be calculated. Such approximation methods are known to those skilled in the art.

With reference to the illustrated example of FIG. 1D, cross section 116 is first identified as a Type I region that includes multiple protrusions. Thus, the convergent spiral tool path segment is computed between the outer boundary of the workpiece and the calculated inner contour as the initial tool path segment. This operation preferably begins with the calculation of the spiral tool path segment starting from the selected position just outside the periphery of the cross section 116. In this context, FIGS. 1E-1 to 1E, wherein the initial spiral tool path segment is an isometric and top view of the raw material 114, respectively, overlaid by the outline 121 of the object 100, indicated entirely by the reference numeral 122. See -2. Note that the spiral tool path is indicated by a solid line representing the center of the rotary cutting tool, the cross section degree of which is designated by reference numeral 124 in FIGS. 1E-2. The selected position, designated by reference numeral 126 in the text, is preferably selected to minimize the time required to move the rotary cutting tool from its previous position.

In the illustrated example of FIGS. 1E-1 through 1E-2, the original tool path segment is a convergent spiral segment computed as described above. As shown in FIGS. 1E-1 through 1E-2, the initial spiral tool path segment 122 finally intersects the island 105 at the intersection point 130 where the point spiral tool path segment 122 terminates. . As shown in FIGS. 1F-1 through 1F-1, an arc 132 surrounding the island 105 is computed.

1F-1 through 1F-2, the inner boundary 134 of the arc 132, which is generally along the outer boundary of the island 105, is computed. A narrow offset remains between the island 105 and the inner boundary 134 of the arc, which can be machined last in a later stage. The outer boundary 136 of the arc 132 is calculated to be offset from the inner boundary 134 by the width of the arc.

As shown in FIGS. 1F-1 through 1F-2, the outer boundary 136 of the arc 132 intersects the island 107 at points 138, 139. Thus, additional arcs 140 are computed to surround islands 107 such that arcs 132 and 140 are combined to form one continuous arc that surrounds islands 105 and 107. As clearly shown in FIGS. 1F-1 through 1F-2, the combination of the initial spiral tool path segment 122 and the subsequent arcs 132 and 140 surrounding the islands 105 and 107 is referred to by reference numeral 142. Form a new type I region, indicated by.

Region 142 includes multiple islands 109, 111, and 113. As clearly shown in FIGS. 1F-1 through 1F-2, bottleneck 150 is detected in region 142. Thus, as shown in FIGS. 1G-1 through 1G-2, the separation channel 152 is computed at the bottleneck 150 position, so that two independent regions, designated by reference numerals 154 and 156, are designated by region 142. It effectively partitions into phosphorus type I domains.

1H-1 through 1H-2, the spiral tool path segment for region 154 is first computed while the computation of region 156 is deferred. As shown in FIGS. 1H-1 through 1H-2, the starting point 160 is selected and the spiral tool path segment 162 is an island 109 at the intersection point 164 at which the point spiral tool path segment 162 terminates. Extends from the initial point 160 as a whole along the outer boundary of the region 154 until it intersects. As shown in FIGS. 1I-1 through 1I-2, an arc 166 surrounding island 109 is computed. The remainder of the area 154 is identified as the type I area designated by reference numeral 170.

Region 170 includes islands 111 and 113. As clearly shown in FIGS. 1I-1 through 1I-2, bottleneck 172 is detected in region 170. Thus, as shown in FIGS. 1J-1 through 1J-2, the separation channel 174 is computed at the bottleneck 172 location, so that two independent regions, designated by the reference numerals 176 and 178, are identified. It effectively partitions into phosphorus type I domains.

1K-1 through 1K-2, first, a spiral path for machining region 176 is computed, while computation of region 178 is postponed. As shown in FIGS. 1K-1 through 1K-2, the region 176 does not include islands, so that its radius as a whole is smaller than the radius of the tool and is small, centered around the central region of the region 176. A converging helix tool path segment is computed to machine an area 176 with an inner boundary of the area 176 that is the circle 177.

As a result, the spiral tool path segment for region 178 is computed. As shown in FIGS. 1L-1 through 1L-2, the starting point 180 is selected and the helix tool path segment 182 is at the intersection point 184 of the point where the helix tool path segment 162 terminates. Extending from the initial point 180 as a whole along the outer boundary of the region 178 until it intersects with 111. As shown in FIGS. 1M-1 through 1M-2, an arc 186 surrounding the protrusion 110 is computed.

If the outer boundary of the arc is computed to be proximate to the outer boundary of the type I region containing the arc, the local widening of the arc is calculated to prevent the formation of a narrow residual wall between the arc and the outer boundary of the region. As is known to those skilled in the art, the formation of narrow residual walls is undesirable because machining them causes damage to the cutting tool and / or the workpiece.

As shown in FIGS. 1M-1 through 1M-2, the outer boundary of arc 186 is computed to be proximate to the outer boundary of region 178. Thus, arc 186 extends to the outer boundary of the region 178 along the region 189 of the narrow residual wall where a narrow residual wall is formed between the arc 186 and the outer boundary of the region 178 without expanding the arc. Locally expanded. Locally expanded call 186 divides the region into two independent Type I regions, designated by reference numerals 190 and 192.

1N-1 through 1N-2, the region 190 is first computed while the computation of region 192 is deferred. As shown in FIGS. 1N-1 through 1N-2, two clipped regions of region 190 designated by reference numerals 196 and 198 are identified. Regions 196 and 198 are computed to be machined by the trocoided tool path segment prior to machining the remainder of region 190 by the spiral tool path segment.

The remainder of region 190 does not include islands, so region 190 with its inner boundary is a small circle 191 whose radius is less than the radius of the tool as a whole and centered around the central region of region 190. Converging spiral tool path segments are computed to machine the remainder of.

As a result, the spiral tool path segment for region 192 is computed. As shown in Figs. 1O-1 to 1O-2, one area of the area 192 designated by reference numeral 200 is identified by clipping. The area 200 is computed by the trojan-shaped tool path segment before being machined the remainder of the area 192 by the spiral tool path segment.

In addition, as shown in FIGS. 1P-1 through 1P-2, additional areas of the area 192 designated by reference numeral 202 are identified by clipping. However, it is calculated that area 202 is machined more efficiently as individual Type I areas. Thus, a separate channel is computed that divides the remainder of region 192 into two Type I regions designated by reference numerals 202 and 214. The region 202 does not include protrusions, and as shown in FIGS. 1Q-1 through 1Q-2, the radius of the tool as a whole is smaller than the radius of the tool and is small, centered around the central region of the region 202. Converging helix tool path segments are computed to machine an area 202 with an inner boundary which is a circle 213.

It is calculated that machining the separation channel 210 and machining region 202 as a type I region result in a machining time that is shorter than the machining time of region 202 by a trocoided tool path segment.

Referring to FIGS. 1R-1 through 1R-2, it is shown that region 214 includes one island 113 that is generally centered within region 214. Thus, a converging spiral tool path segment 216 is computed for machining an area 214 having an internal boundary along the outer periphery of the island 113 as a whole. As shown in FIGS. 1R-2, the spiral tool path segment 216 finally intersects the island 113 at the intersection point 218 at the point where the spiral tool path segment 216 terminates. After machining the segment 216, one or more type II regions adjacent to the islands 113 machined by the trocoided tool path segment may remain.

1S-1 through 1S-2, the machining of the area 156 is shown calculated. As shown in FIGS. 1S-1 through 1S-2, the clipped region of region 156 designated by reference numeral 230 is identified. Region 230 is preferably computed to be machined by the trocoided tool path segment, and the remainder of region 156 is then computed to be machined by the spiral tool path segment.

It will be appreciated that the above calculation constitutes the calculation of the tool path for the machining of the first step down, which is the first phase in the machining of the article 100. Overall, the term "step down" is used to describe a single machining phase at a constant depth. As shown in FIG. 1C, the completion of machining of the article 100 requires three step downs. Thus, following and similarly to the above-described calculations, the tool path designer may calculate the machining of the second stepdown 119 and then calculate the third stepdown 120 to determine the work of the object 100. Complete rough machining complete. Preferably, the vertical distance between subsequent step downs is generally 1 to 4 times the diameter of the rotary cutting tool.

Following rough machining of the workpiece, an additional stage of the remaining rough machining is computed, which reduces the large residual steps generated by a series of step downs on the inclined surface of the article 100.

2A-2L-2, another tool path operation is illustrated in accordance with a preferred embodiment of the present invention. 2A and 2B are illustrations of an isometric and top view of an article 400, which is another example of an article that can be made in accordance with the present invention, respectively. The setting of the article 400 is chosen to represent additional various specific features of the present invention. Note that any suitable three-dimensional article that can be machined by conventional three-axis machine tools can be manufactured according to a preferred embodiment of the present invention.

As shown in FIGS. 2A and 2B, the article 400 is shown to have a generally flat base portion 402 extending from one protrusion, designated by reference numeral 404 in the text. 2C shows the raw material 410 superimposed by the cross section 420 of the article 400. Cross section 402 is characterized by having an outer boundary 422 and an island 405 corresponding to the cross section of the protrusion 404 at the depth of the cross section 420.

In the example shown in FIG. 2C, cross section 420 is first identified as a Type III region that includes one island. As discussed above, a plurality of nested offset contours are computed between the outer boundary of region 424 and the innermost contour of region 424. The innermost contour is first calculated to overlap the outer boundary of the island 405. Thus, as shown in FIGS. 2D-1 through 2D-2, the arc 428 surrounding the island 405 is computed and the innermost contour 430 is located just outside the outer boundary of the arc 428. Is computed.

As shown in FIGS. 2D-1 through 2D-2, the nested inner contour 440 external to the innermost contour 430 and the innermost contour 430 defines the type III region 442. Form. As shown in FIGS. 2E-1 through 2E-2, the diverging tool path segment 443 first draws an outward spiral between the innermost contour 430 and the nested inner contour 440, whereby Computed to create two remaining regions 444 and 446. As shown in Figures 2F-1 through 2F-2, the remaining area 444 is computed to be machined as a type II area by employing a trocoid-type tool path segment. Similarly, as shown in FIGS. 2G-1 through 2G-2, the remaining area 446 is computed to be machined as a type II area by employing a trocoid-type tool path segment.

2H-1 through 2H-2, the diverging helix tool path segment is computed to machine a type III region 448 formed between the nested inner contour 440 and the nested inner contour 450. Is shown. As a result, as shown in FIGS. 2I-1 through 2I-2, a diverging helix tool to machine the type III region 452 formed between the nested inner contour 450 and the nested inner contour 460. Path segments are similarly computed.

2J-1 through 2J-2, the diverging helix tool path segment is computed to machine the type III region 468 formed between the nested inner contour 460 and the outer boundary 422, thereby creating two Creating residual areas 470 and 472 is shown. As shown in FIGS. 2K-1 through 2K-2, the remaining area 470 is computed to be machined as a type II area by employing a trocoid-type tool path segment. Similarly, as shown in FIGS. 2L-1 through 2L-2, the remaining area 470 is computed to be machined as a type II area by employing a trocoid-type tool path segment to perform the machining operation of the article 400. To complete.

Those skilled in the art will understand that the present invention is not limited by the specific details shown and described above. Rather, the present invention also contemplates various combinations and subcombinations of the above-described features and modulations and variations thereof that occur to those skilled in the art upon reading the above.

Claims (19)

An automated computer-implemented method of generating instructions for controlling a computer numerical control machine to manufacture an object from a workpiece, the method comprising at least one of the following six groups of steps, the group comprising:
Selecting a maximum permitted engagement angle between the rotary cutting tool and the workpiece;
Selecting a minimum allowable engagement angle between the rotary cutting tool and the workpiece; And
Setting a tool path for the rotary cutting tool for the workpiece, wherein the engagement angle between the rotary cutting tool and the workpiece is gradually changed between the maximum allowable engagement angle and the minimum allowable engagement angle; ;
Selecting an area of the workpiece to be removed by the rotary cutting tool; And
Establishing an asymmetric spiral tool path for the rotary cutting tool in the region of the workpiece, wherein the asymmetric spiral tool path is removed by the rotary cutting tool moving along the asymmetric spiral tool path. Maximizing a portion of the region;
By employing a trochoidal tool path the first machining time required to remove the at least one semi-open area is between the at least one semi-open area and all closed outer boundary segments of the at least one semi-open area. Identifying at least one semi-open area that is longer than a second machining time required to isolate the at least one semi-open area by removing the separation channels of the at least one semi-open area. ; And
At least one separating channel between the at least one semi-open area and all closed outer boundary segments of the at least one semi-open area is formed in the at least one semi-open area to be removed, thereby forming the remaining open area to be removed. Step;
Selecting an area of the workpiece to be removed by the rotary cutting tool;
Selecting a first portion of the region of the workpiece to be removed by an asymmetrical spiral tool path, wherein selecting the first portion of the region is the machining time required to remove the region of the workpiece Operating to minimize; And
Establishing at least one trocoid-like tool path to remove a residual portion of the area of the workpiece;
Considering a cross section of the object to be manufactured from the workpiece;
Forming discrete regions of the cross-section on the surface of the workpiece that will not be removed as islands;
Starting to set a tool path in an area without islands; And
When the tool path meets an island, establishing a call tool path that forms an moat surrounding the island; And
The first machining time required to remove the at least one open area is such that the at least one opening is removed by removing the separation channel and removing the two independent areas by the rotary cutting tool between two independent areas. Identifying at least one open area that is longer than a second machining time required to divide the area into two independent areas; And
Forming at least one open region in the at least one open region by forming at least one separation channel extending between two points on an edge of an outer boundary of the at least one open region, thereby forming the at least one open region at least two independent regions Dividing into; The method of claim 1, wherein the method comprises at least two of the six groups of steps. The method of claim 1, wherein the method comprises at least three of the six groups of steps. The method of claim 1, wherein the method comprises at least four of the six groups of steps. 5. The method of claim 1, wherein in response to at least one consideration of the characteristics of the computer numerical control machine, the rotary cutting tool, and the workpiece material, setting the tool path further comprises:
Minimizing the rate of change of the engagement angle over time, while applying other constraints;
Gradually changing a feed rate of the rotary cutting tool in response to a change in the engagement angle;
Maintaining a generally constant workload for the rotary cutting tool; And
Minimizing the manufacturing cost of the article, whereby the cost is a combination of the cost of operating the machine during the period of manufacture and the wear cost imposed on the rotary cutting tool during the period of manufacture;
Automated computer implemented method comprising at least one of. 6. The method according to any one of claims 1 to 5,
The tool path comprises a plurality of tool path segments; And
The tool path setting step includes recursively setting each of the tool path segments;
In response to taking into account at least one of the properties of the computer numerical control machine, the rotary cutting tool and the material of the workpiece, the step of setting each of the tool path segments also includes:
Minimizing the rate of change of the engagement angle over time, while applying other constraints,
Gradually changing a feed rate of the rotary cutting tool in response to a change in the engagement angle, and
Maintaining an overall constant work load for the rotary cutting tool,
Automated computer implementation method comprising a. The method according to claim 6,
Each of the tool path segments comprises a plurality of tool path subsegments; And
Recursively setting each of the tool path segments includes recursively setting each of the tool path subsegments; And
In response to taking into account at least one of the properties of the computer numerical control machine, the rotary cutting tool and the material of the workpiece, the step of setting each of the tool path subsegments further comprises:
Minimizing the rate of change of the engagement angle over time, while applying other constraints,
Gradually changing a feed rate of the rotary cutting tool in response to a change in the engagement angle; And
Maintaining an overall constant work load for the rotary cutting tool,
Automated computer implemented method comprising at least one of. The method according to any one of claims 1 to 7,
The asymmetric spiral tool path comprises a plurality of spiral tool path segments;
The at least one trocoid-type tool path comprises a plurality of trocoid-type tool path segments;
Establishing the asymmetrical spiral tool path comprises recursively setting each of the spiral tool path segments; And
And said at least one trocoid-type tool path setting step includes recursively setting each of said trocoid-type tool path segments. The method according to any one of claims 1 to 8,
Forming a composite region comprising the island, the moat surrounding the island and regions that have already been removed from the workpiece as removed regions; And
Setting a tool path to remove residual areas of the workpiece that do not include the removed areas;
Automated computer implementation method further comprising a. An automated computer implemented device for generating instructions for controlling a computer numerical control machine to manufacture an object from a workpiece, the device comprising:
A tool routing engine for selecting an area of the workpiece to be removed by the rotary cutting tool and operating at least one of the following combinations, the combinations comprising:
Establishing a tool path for the rotational cutting tool with respect to the workpiece, wherein the engagement angle is gradually changed between a preselected maximum allowable engagement angle and a preselected minimum allowable engagement angle;
Establishing an asymmetrical spiral tool path for the rotary cutting tool in the area of the workpiece, the asymmetrical spiral tool path being removed by the rotary cutting tool moving along the asymmetrical spiral tool path. Maximizing a portion of said region of;
The first machining time required to remove the at least one semi-open area by employing a trocoid-type tool path is such that the separation channel between all at least one semi-open area and all closed outer boundary segments of the at least one semi-open area. Identifying at least one semi-open area that is longer than a second machining time required to isolate the at least one semi-open area by removing them and removing the remaining portion of the at least one half-open area; And
At least one separation channel between the at least one half-open area and all closed outer boundary segments of the at least one half-open area is formed in the at least one half-open area to be removed, thereby forming the remaining open area to be removed. Combination;
Selecting a first portion of the region of the workpiece to be removed by an asymmetrical spiral tool path, wherein selecting the first portion of the region of the workpiece comprises removing the region of the workpiece Operating to minimize the required machining time; And
Establishing at least one trocoid-like tool path to remove residual portions of the area of the workpiece;
Considering a cross section of the object to be manufactured from the workpiece;
Forming as discrete islands of the cross-section on the surface of the workpiece that will not be removed;
Starting to set a tool path in an area without islands; And
When the tool path meets an island, establishing an arc tool path forming an arc surrounding the island; And
The first machining time required to remove the at least one open area is achieved by removing the separation channel and removing the two independent areas by the rotary cutting tool between two independent areas. Identifying at least one open region longer than a second machining time required to divide the open region into two independent regions; And
Forming at least one open region in the at least one open region by forming at least one separation channel extending between two points on an edge of an outer boundary of the at least one open region, thereby forming the at least one open region at least two independent regions Dividing into; 11. The computer-implemented apparatus of claim 10, wherein the method comprises at least two of the combinations. 11. The automated computer implemented apparatus of claim 10, wherein the method comprises at least three of the combinations. 13. The method of any one of claims 10 to 12, wherein the setting of the tool path corresponds to the consideration of at least one of the characteristics of the computer numerical control machine, the rotary cutting tool and the workpiece material.
Minimizing the rate of change of the engagement angle over time, while applying other constraints;
Gradually changing a feed rate of the rotary cutting tool in response to a change in the engagement angle;
Maintaining an overall constant work load for the rotary cutting tool; And
Minimizing the manufacturing cost of the article, whereby the cost is a combination of the cost of operating the machine during the period of manufacture and the wear cost imposed on the rotary cutting tool during the period of manufacture;
An automated computer implemented device comprising at least one of the following. 14. The method according to any one of claims 10 to 13,
The tool path comprises a plurality of tool path segments; And
The tool path setting step includes recursively setting each of the tool path segments;
In response to taking into account at least one of the properties of the computer numerical control machine, the rotary cutting tool and the material of the workpiece, the step of setting each of the tool path segments also comprises:
Minimizing the rate of change of the engagement angle over time, while applying other constraints;
Gradually changing a feed rate of the rotary cutting tool in response to a change in the engagement angle; And
Maintaining an overall constant work load for the rotary cutting tool;
And at least one of the; 15. The method of claim 14,
Each of the tool path segments comprises a plurality of tool path subsegments; And
Recursively setting each of the tool path segments includes recursively setting each of the tool path subsegments; And
In response to taking into account at least one of the properties of the computer numerical control machine, the rotary cutting tool and the material of the workpiece, setting each of the tool path subsegments further comprises:
Minimizing the rate of change of the engagement angle over time, while applying other constraints;
Gradually changing a feed rate of the rotary cutting tool in response to a change in the engagement angle; And
Maintaining an overall constant work load for the rotary cutting tool;
And at least one of the; 16. The engine according to any one of claims 10 to 15, wherein the setup engine is also:
Forming a composite region comprising the island, the arc surrounding the island and the regions already removed from the workpiece as removed regions; And
And set a tool path to remove remaining areas of the workpiece that do not include the removed areas. An automated computer controlled machine for manufacturing an object from a workpiece, the machine comprising:
Selecting an area of the workpiece to be removed by the rotary cutting tool; A controller that operates at least one of the following combinations, the combinations comprising:
Directing the rotary cutting tool along an asymmetrical spiral tool path in the region of the workpiece, the workpiece being removed by the rotary cutting tool moving along the asymmetrical spiral tool path Maximizing a portion of said area of the piece;
Directing the rotary cutting tool along a tool path for the workpiece where the engagement angle between the rotary cutting tool and the workpiece is gradually varied between a preselected maximum allowable engagement angle and a preselected minimum allowable engagement angle; Combination;
Selecting a first portion of the region to be removed by the asymmetrical spiral tool path, wherein selecting the first portion of the region is operative to minimize the machining time required to remove the region; And
Directing the rotary cutting tool along at least one trocoid-like tool path in the remaining portion of the area of the workpiece;
The first machining time required to remove the at least one semi-open area by employing a trocoid-type tool path is such that the separation channel between all at least one semi-open area and all closed outer boundary segments of the at least one semi-open area. Identifying at least one semi-open area that is longer than a second machining time required to isolate the at least one semi-open area by removing them and removing a residual portion of the at least one half-open area; And
At least one separation channel between the at least one half-open area and all closed outer boundary segments of the at least one half-open area is formed in the at least one half-open area to be removed, thereby forming the remaining open area to be removed. Combination;
Considering a cross section of the object to be manufactured from the workpiece;
Forming as discrete islands of the cross-section on the surface of the workpiece that will not be removed;
Starting to set a tool path in an area without islands; And
When the tool path meets an island, establishing an arc tool path forming an arc surrounding the island; And
The first machining time required to remove the at least one open area is achieved by removing the separation channel and removing the two independent areas by the rotary cutting tool between two independent areas. Identifying at least one open region longer than a second machining time required to divide the open region into two independent regions; And
Forming at least one open region in the at least one open region by forming at least one separation channel extending between two points on an edge of an outer boundary of the at least one open region, thereby forming the at least one open region at least two independent regions And a dividing into an automated computer controlled machine. An article manufactured from a workpiece machined using a computer controlled machine tool by selecting an area of the workpiece to be removed by a rotary cutting tool and by at least one of the following steps,
Directing a rotary cutting tool along an asymmetrical spiral tool path in an area of the workpiece, wherein the asymmetrical spiral tool path is removed by the rotary cutting tool moving along the asymmetrical spiral tool path; Maximizing a portion of the area;
Directing the rotary cutting tool along a tool path, wherein the engagement angle between the rotary cutting tool and the workpiece is gradually varied between a preselected maximum allowable engagement angle and a preselected minimum allowable engagement angle;
Selecting a first portion of the region to be removed by the asymmetrical spiral tool path, wherein selecting the first portion of the region is operative to minimize the machining time required to remove the region; And
Directing the rotary cutting tool along at least one trocoid-like tool path in the remaining portion of the area of the workpiece;
The first machining time required to remove the at least one semi-open area by employing a trocoid-type tool path is such that the separation channel between all at least one semi-open area and all closed outer boundary segments of the at least one semi-open area. Identifying at least one semi-open area that is longer than a second machining time required to isolate the at least one semi-open area by removing them and removing a residual portion of the at least one half-open area; And
At least one separation channel between the at least one half-open area and all closed outer boundary segments of the at least one half-open area is formed in the at least one half-open area to be removed, thereby forming the remaining open area to be removed. Combination;
Considering a cross section of the object to be manufactured from the workpiece;
Forming as discrete islands of the cross-section on the surface of the workpiece that will not be removed;
Starting to set a tool path in an area without islands; And
When the tool path meets an island, establishing an arc tool path forming an arc surrounding the island; And
The first machining time required to remove the at least one open area is achieved by removing the separation channel and removing the two independent areas by the rotary cutting tool between two independent areas. Identifying at least one open region longer than a second machining time required to divide the open region into two independent regions; And
Forming at least one open region in the at least one open region by forming at least one separation channel extending between two points on an edge of an outer boundary of the at least one open region, thereby forming the at least one open region at least two independent regions Dividing into; A method of machining a workpiece by employing a computer controlled machine tool, the method comprising:
Selecting an area of the workpiece to be removed by the rotary cutting tool; and at least one of the following steps; Including,
The following steps are:
Directing the rotary cutting tool along an asymmetrical spiral tool path in the region of the workpiece, the asymmetrical spiral tool path being removed by the rotary cutting tool moving along the asymmetrical spiral tool path. Maximizing a portion of said area of the piece;
Directing the rotary cutting tool along a tool path, wherein the engagement angle between the rotary cutting tool and the workpiece is gradually varied between a preselected maximum allowable engagement angle and a preselected minimum allowable engagement angle;
The first machining time required to remove the at least one semi-open area by employing a trocoid-type tool path is such that the separation channel between all at least one semi-open area and all closed outer boundary segments of the at least one semi-open area. Identifying at least one semi-open area that is longer than a second machining time required to isolate the at least one semi-open area by removing them and removing a residual portion of the at least one half-open area; And
At least one separation channel between the at least one half-open area and all closed outer boundary segments of the at least one half-open area is formed in the at least one half-open area to be removed, thereby forming the remaining open area to be removed. Combination;
Selecting a first portion of the region of the workpiece to be removed by an asymmetrical spiral tool path, wherein selecting the first portion of the region is operative to minimize the machining time required to remove the region Making; And
Directing the rotary cutting tool along at least one trocoid-like tool path in the remaining portion of the area;
Considering a cross section of the object to be manufactured from the workpiece;
Forming as discrete islands of the cross-section on the surface of the workpiece that will not be removed;
Starting to set a tool path in an area without islands; And
When the tool path meets an island, establishing an arc tool path forming an arc surrounding the island; And
The first machining time required to remove the at least one open area is achieved by removing the separation channel and removing the two independent areas by the rotary cutting tool between two independent areas. Identifying at least one open region longer than a second machining time required to divide the open region into two independent regions; And
Forming at least one open region in the at least one open region by forming at least one separation channel extending between two points on an edge of an outer boundary of the at least one open region, thereby forming the at least one open region at least two independent regions Dividing into; and employing a computer-controlled machine tool to machine the workpiece.

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